Portable devices, such as computers, tablets, and cellular telephones are commonly equipped with a camera on the front directed to the user and a camera on the back directed away from the user. The front camera is typically used for video conferencing and self-portraits, while the rear camera is typically used for video and still photography.
Small digital cameras have become commonplace on portable telephone, communication, entertainment, and media devices. There is a corresponding increase in the use of cameras for security, navigation, safety, and other uses. Two cameras directed at the same scene from different positions provide stereo vision allowing for depth perception. An array of cameras or image sensors mounted to a single device can also enable many other compelling 3D user experiences, including temporal resolution and increased dynamic range. A variety of different portable photographic, computing, and media player devices can be adapted to integrate camera array technology on their platforms.
A very few products offer two cameras on the back side of the portable device or of a camera to allow stereo or three-dimensional images or video to be taken and recorded. A device with two or more cameras for depth perception allows for a variety of different additional functions. As an example, a depth map can be overlaid on a still image as a tool for enhancing the image. The depth map can be used for motion effects (parallax views), for depth measurement and for applying digital filters that select based on depth, such as refocus, layered filters, and view synthesis, among others.